What is COPD: analysis of chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease (COPD) is a disease of the respiratory system characterized by an irreversible obstruction of the airways, of variable size depending on the severity. The disease is usually progressive and associated with a state of chronic inflammation of the lung tissue. The long-term consequence is a true remodeling of the bronchi, which causes a substantial reduction in respiratory capacity.
Such clinical picture is worsened by the increased predisposition to respiratory infections of viral, bacterial or fungal origin. Currently, there is no effective cure, but several treatments are available to control symptoms and avoid dangerous complications. It goes without saying that prevention is fundamental to minimize risk factors (in the first place, cigarette smoking).
What are the symptoms of COPD?
Before diagnosis, the two main symptoms of COPD are cough and dyspnea, sometimes followed by wheezing. Cough is often chronic, more intense in the morning and characterized by mucus production. Dyspnea gradually appears over several years and, with regards to more serious cases, can even limit normal daily activities. Generally, such people are prone to chronic infections of the respiratory system, which occasionally cause relapses accompanied by an aggravated symptomatology. As the disease progresses such episodes tend to become more and more frequent.
COPD: care and treatment
COPD originates from two major diseases such as chronic bronchitis and pulmonary emphysema. When the disease progresses, both forms can lead to the onset of respiratory failure with decreased oxygenation and accumulation, chronic and acute, of carbon dioxide in the blood (hypercapnia); the latter is a predictive sign of a bad prognosis of the disease and currently treated with non-invasive ventilation (NIV). Applied at night at the patient’s home, it prevents a further increase of “harmful” gas and in some cases even improves patient survival. Unfortunately, not all patients tolerate it, as the insufflation of a flow of air delivered by a respirator inside the airways through a facial or nasal mask interferes with sleep and generally with patient’s comfort. It is estimated that around 30-35% is forced to abandon the treatment.
Consequently, a second route has been discovered, the so-called pulmonary dialysis: a catheter which draws the blood rich in CO2 into the vein and returns it through the same way purified from carbon dioxide, thus preventing the need to resort to invasive ventilation. The extracorporeal CO2 removal technique could seriously change the history of such disease from the precise time in which it will be able to prevent the failure of non-invasive ventilation and therefore the need to get to the invasive one. The first studies carried out by Prof. V.M. Ranieri and by Prof. S. Nava at Molinette in Turin and Bologna showed that the association of extracorporeal CO2 removal with non-invasive ventilation in intensive care significantly reduced the need for transition to invasive ventilation. The purpose is to “bring back” the clock of natural history of the disease, preventing the failure of non-invasive ventilation or, even better, preventing the need for invasive ventilation way before.
What is ARDS: ACUTE RESPIRATORY DISTRESS SYNDROME
cute respiratory distress syndrome is a life threatening disease for which the lungs are unable to function properly. It is caused by an injury to the capillary wall due to illness or bruising. This causes leakage of liquid from the walls capillaries, which lead to an accumulation of fluid and the subsequent collapse of the air pockets, making the lungs unable to exchange oxygen and carbon dioxide. The term “acute respiratory failure” is often used as a synonym for ARDS / ALI. However, such term refers more generally to lung insufficiency due to any cause, for instance chronic obstructive pulmonary disease (COPD).
What are the symptoms and causes of ARDS?
Most unlikely the acute respiratory distress syndrome will occur spontaneously, being often the consequence of other pathologies, serious accidents or bruises. Most likely, patients affected by ARDS are already hospitalized. Symptoms suggesting the presence of ARDS include dyspnea (wheezing) or cyanosis (purple or bluish discoloration) of fingers or lips.
There are two types of events which can cause acute respiratory distress syndrome: direct lung injury and indirect injuries of other parts of the body.
• Displacement of stomach contents inside the lungs (aspiration of gastric contents)
• Severe lung trauma
• Inhalation of toxic fumes or gases
• Adipose embolism, in which a quantity of body fat is found inside the apparatusrespiratory, causing problems
• Diffuse edema throughout the body, caused by hyperreactivity of the immune system (severe sepsis)
• Multiple blood transfusions
• Inflammation of the pancreas (pancreatitis)
• Blood coagulation
• Drug overdoses
ARDS: care e treatment
Although the removal of carbon dioxide is a technique known since the 70s, in recent years thanks to the invention of systems which are less invasive and easier to use, interest in removal extracorporeal CO2 has grown exponentially.
ECCO2R has been proposed in both patients with severe hypoxemic acute respiratory failure ARDS type and in patients with acute hypercapnic respiratory failure.
In patients with ARDS or ALI (acute lung injury), the volu-trauma exerted by ventilation mechanics is in turn the cause of injuries (VILI = Ventilator-induced Lung Injury). Therefore, in patients with acute respiratory distress syndrome (ARDS) or ALI the rationale for using the ECCO2-R system is to allow ventilation with very low tidal volumes (“ultra-protective ventilation”).
Protective ventilation using low tidal volumes inevitably leads to hypercapnia and acidosis. Extracorporeal CO2 extraction is a solution which can be easily implemented today to guarantee acid-base homeostasis in order to avoid both lung damage induced by the ventilator (VILI) and deleterious effects of hypercapnia resulting in the reduction of minute ventilation (cerebral and systemic vasodilation, cardiovascular depression, arrhythmias, pulmonary vasoconstriction, etc.). Further fields of application of ECCO2-R are:
• the bridge for lung transplantation
• thoracic surgery of the trachea, in polytraumatized patients (lung brain).
PneumoHelp and the new lung dialysis
The innovative ECCO2R system called Pneumohelp® is a simple veno-venous system, with low flow blood, which, thanks to the presence of an oxygenator and a monoroller system, allows removal extracorporeal of about 35% carbon dioxide (CO2), without danger for the patient.
The collection and re-infusion of the treated blood takes place through a single inserted double lumen catheter in the femoral or jugular vein; this results in less invasiveness than the arteriovenous by-pass.
Such procedure, in patients with acute respiratory insufficiency, allows to reduce hypercapnia (excess of carbon dioxide in the blood), providing the protection of the lung by reducing the ventilation pressure.
The PneumoHelp system, in pulmonary dialysis mode, is a low flow veno-venous system which requires only a double lumen catheter; it is minimally invasive and free of side effects. Pulmonary dialysis represents the technological solution which “clears” the extracorporeal support technique, so far relegated to severe patients with acute respiratory insufficiency (ARDS-COPD exacerbated). Nowadays with the PneumoHelp system, all centers with experience in renal hemofiltration can use extracorporeal respiratory support for all their patients and thus increase the effectiveness of resuscitation treatment, in acute cases and (taking up the classic concept of intermittent dialysis) in chronic ” stable ” COPD patients who, by undergoing a short lung dialysis treatment two or three times a week, can improve their quality of life by keeping their carbon dioxide levels in their blood lower, and therefore closer to the physiological, and reduce relapses in terms of exacerbation. PneumoHelp therefore represents a valid extracorporeal support not only for Acute Respiratory Distress Syndrome (ARDS) but also in the treatment of exacerbations in chronic obstructive bronchopathies (COPD), in cases of Multiorgan Insufficiency (MODS – Multiple Organ Distress Syndrome), in Bridge to Lung Transplantation and as lung dialysis in chronic stable COPD patients. The PneumoHelp system is also used as support therapy in multi-organ pathologies (MOST – Multiply organ support therapy), support therapy in multi-organ pathologies: a “dialysis” with multiple filters, capable of purifying the blood from waste or from elements which stress not only the kidneys but also the heart, lungs and liver.
PneumoHelp as a bridge to lung transplantation
According to data from the World Health Organization (WHO), lung diseases are the third leading cause of death in developed countries. Pulmonary transplantation is currently considered a valid strategy to improve quality of life and prolong survival, as a result the number of patients on the waiting list is constantly increasing in parallel with the proportion of high urgency patients (HU). In 2000 the HU procedures were 10%, in 2007 they became 60% of the total performed. HU patients often require mechanical ventilation, even though in many centers it is considered a contraindication for transplantation.
The use of extracorporeal care methods in patients with acute respiratory failure secondary to viral infection or terminal pneumopathy awaiting on transplantation has become increasingly common in recent years. Recently, Italian guidelines have been drawn up on the criteria of urgent pulmonary transplantation which take into consideration patients in whom these methods are used as a bridge to urgent transplantation.
On the one hand, it is therefore considered very useful to hold a status meeting on the indications and the short and long-term outcome of such extracorporeal supports in order to inform the medical specialists and the nursing staff operating in not accredited centers as a regional reference for the use of extracorporeal supports, on the indications and results of such care methods; on the other hand it is advisable to encourage the creation of a national working group for the flow of information on possible adverse events of the method, its indications and contraindications paying attention to patients on the lung transplant list.
There have been various clinical studies which have evaluated the efficacy of the new extracorporeal CO2 removal techniques in the transplantation bridge with the extracorporeal decapneization technique (such as Pneumohelp).
Decapneization as a pulmonary support in cases of flu A / H1N1:
The flu A/H1N1 virus can provoke severe lung failure in patients. In several Italian hospitals there is an extracorporeal decapneization system, commonly used for respiratory failure, which can be used to treat complications with flu A / H1N1.
The PneumoHelp system is a minimally invasive, all-Italian method, which allows extracorporeal removal of carbon dioxide with an easy-to-manage technique, whose effectiveness is overt and which can easily be made transportable and quickly applied to the patient.